初探：使用NPOI导出Excel（已有Excel模板）

Posted 2020-09-14

/// <summary>

/// 应用开源NPOI，导出Excel

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void btnNPOIExport_Click(object sender, EventArgs e)

{

if (!File.Exists(sExePath + "NPOI.dll"))

{

MessageBox.Show("导出所需动态链接库NPOI.dll不存在，不支持导出。", "提示");

return;

}

if (!File.Exists(sExePath + sExcelName))

{

MessageBox.Show("DataUsageReportingFileSample.xls模板文件不存在，请确认与.EXE同路径下包含此文件。", "提示");

return;

}

 

// 填充数据

using (SaveFileDialog saveExcel = new SaveFileDialog())

{

saveExcel.Filter = "Excel文件 (*.xls)|*.xls";

string sNewFileName = string.Empty;

if (saveExcel.ShowDialog() == DialogResult.OK)

{

sNewFileName = saveExcel.FileName;

// 文件已被打开，则提示关闭

if (CFileHasOpened.FileHasOpen(sNewFileName))

{

MessageBox.Show("文件已被打开，请关闭后再重试保存。", "提示");

return;

}

// 复制模板，以后的操作都在复制的文件上进行

File.Copy(sExePath + sExcelName, sNewFileName, true);

 

InitializeWorkbook(sNewFileName);

if (null == hssfworkbook)

{ return; }

ISheet modelSheet = hssfworkbook.GetSheet("Market Data Usage");

// 单元格格式

ICellStyle CenterStyle = hssfworkbook.CreateCellStyle();

CenterStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;

 

if (null == modelSheet)

{ return; }

if (null == QueriedPermissions)

{ return; }

 

for (Int32 rowIndex = 0; rowIndex < QueriedPermissions.Count; rowIndex++)

{

IRow tmpRow = modelSheet.GetRow(rowIndex + 5);

if (null == tmpRow)

{ continue; }

for (Int32 colIndex = 0; colIndex < QueriedPermissions[rowIndex].Count; colIndex++)

{

ICell tmpCell = tmpRow.GetCell(colIndex);

if (null == tmpCell)

{ continue; }

if (colIndex < 7)

{

tmpCell.SetCellValue(QueriedPermissions[rowIndex][colIndex].ToString().Trim());

}

else

{

tmpCell.SetCellValue(Convert.ToInt32(QueriedPermissions[rowIndex][colIndex].ToString().Trim()));

//tmpCell.CellStyle = CenterStyle;

}

}

}

 

//Force excel to recalculate all the formula while open

modelSheet.ForceFormulaRecalculation = true;

 

WriteToExcelWithNPOI(sNewFileName);

}

}

}

 

private static HSSFWorkbook hssfworkbook;

/// <summary>

/// 初始化工作簿

/// </summary>

private void InitializeWorkbook(string sNewFileName)

{

FileStream file = new FileStream(sNewFileName, FileMode.Open, FileAccess.Read);

if (null == file)

{ return; }

hssfworkbook = new HSSFWorkbook(file);

if (null == hssfworkbook)

{ return; }

//create a entry of DocumentSummaryInformation

DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();

dsi.Company = "test";

hssfworkbook.DocumentSummaryInformation = dsi;

 

//create a entry of SummaryInformation

SummaryInformation si = PropertySetFactory.CreateSummaryInformation();

si.Subject = "test";

hssfworkbook.SummaryInformation = si;

}

 

/// <summary>

/// 把工作簿写到本地文件

/// </summary>

private void WriteToExcelWithNPOI(string sNewFileName)

{

FileStream file = new FileStream(sNewFileName, FileMode.Create);

hssfworkbook.Write(file);

file.Close();

}